In the past year, npm has come under fire for various reasons.
- It can be slow (just try installing large packages over a poor Wi-Fi connection)
- Its installation process can lead to different results for different developers on the same project
- It doesn't work offline, even if you've downloaded the package before
In response to these issues, Facebook came out with a package manager called Yarn. Yarn is essentially a wrapper around npm, giving the same basic functionality with an extra layer of goodness. Let's go ahead and install it so that we can use it to manage our packages!
Visit https://yarnpkg.com/en/docs/install for installation instructions. For macOS, note that you'll need Homebrew (which is like npm for macOS packages--packages everywhere!), which you can get at https://brew.sh/.